1. Field of the Invention
The present invention relates to an electromagnetic induction type supply side charging apparatus for charging a battery provided in a moving body, such as a vehicle, in an electromagnetic induction system, and an electromagnetic induction type charging system having such a supply side charging apparatus.
2. Description of the Related Art
Conventionally, an electromagnetic induction system has been adopted as a charging system for a battery, for example, in an electric vehicle. The electromagnetic induction type charging operation is carried out between a supply side charging apparatus installed on the ground and a receiving side charging apparatus provided in the vehicle. Upon charging, a supply side coupler element provided on the supply side charging apparatus is connected to a receiving side coupler element provided on the receiving side charging apparatus, so that electricity is supplied from the supply side coupler element to the receiving side coupler element in an electromagnetic induction system. High frequency current induced in the receiving side coupler element is converted into direct current and is used to charge a battery.
The supply side charging apparatus converts power-frequency voltage 200V AC into high voltage-high frequency AC and supplies the same to the supply side coupler element. To this end, as shown in FIG. 5, the conventional supply side charger 50 is comprised of a power circuit board 52 on which a power conversion circuit, composed of a rectifying/power factor improving circuit and a resonant converter, etc., is formed in a housing 51. The power circuit board 52 is provided thereon with electronic devices, such as a diode which constitutes the rectifying/power factor improving circuit, and a smoothing condenser 53, etc., and electronic devices such as an FET which constitutes a DC-AC converter, etc.
The housing 51 of the supply side charging apparatus 50 is in the form of a box elongated in the vertical direction to minimize the contact area with the ground. Consequently, the power circuit board 52 is also elongated in the vertical direction and is secured in the housing 51 in an upright position.
Among the electronic devices provided on the power circuit board 52, for example, the smoothing condenser 53 is greater in weight and volume than other electronic devices. Therefore, if the heavy condenser 53 is mounted to the vertically elongated power circuit board 52, the latter is deflected due to the weight. The deflection of the power circuit board 52 causes welded portions of electronic device mounted to the power circuit board 52 to be subject to stress. Consequently, there is a possibility that the electrical connection at the welded portions fails, thus resulting in a reduced reliability of the power circuit board 52.
To solve this problem, it can be considered that a plurality of small capacity condensers are interconnected in parallel to obtain a total capacity identical to that of one heavy condenser 53 to thereby reduce the load applied to the circuit board. However, the parallel connection of the plural condensers contrary to requirements of an increase in the packaging density and miniaturization of the circuit board. Moreover, in an arrangement in which the plural condensers are interconnected in parallel, it is impossible to apply a load uniformly to the condensers, due to irregular characteristics of the condensers. Therefore, this arrangement is not preferable in view of provision of highly reliable electric characteristics.
It is an object of the present invention to provide an electromagnetic induction type supply side charging apparatus in which the reliability of electric functions of a circuit board on which a power conversion circuit is formed can be enhanced, and an electromagnetic induction type charging system having the supply side charging apparatus.
To achieve the object mentioned above, according to an aspect of the present invention, there is provided an electromagnetic induction type supply side charging apparatus in which a power circuit board on which a power conversion circuit is formed to convert the AC of a power source into a high frequency AC is provided in a housing, so that the electric power obtained from the power source AC is supplied in an electromagnetic induction system wherein, among electric/electronic devices which constitute the power conversion circuit, one or more electric/electronic device or devices which is or are relatively heavy or bulky is or are secured to the housing or a structure body secured thereto.
With this arrangement of the invention, it is possible to prevent the power circuit board from being continuously subject to an extraordinarily large bending force due to a relatively heavy or bulky electric/electronic devices, and hence the power circuit board on which the power conversion circuit is formed tends not to be unusually deflected. Consequently, the welded portions of the electric/electronic devices mounted on the power circuit board are not continuously subject to an extraordinary stress, so that no failure of the electric connection at the welded portions of the electric/electronic devices tends to occur.
The present invention may be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.